CVE-2025-69229: Aiohttp Denial of Service Vulnerability

MODERATE
Advisory Identifier: GHSA-g84x-mcqj-x9qq
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CWE-770
Published
Advisory Summary

CVE-2025-69229 is a MODERATE denial of service vulnerability (CWE-770: Allocation of Resources Without Limits or Throttling) affecting Aiohttp libraries in the PyPI ecosystem. The issue involves aiohttp vulnerable to dos through chunked messages. Remediation is available by upgrading affected packages to version 3.13.3.

CVE-2025-69229 at a Glance

CVE Identifier CVE-2025-69229
GHSA Identifier GHSA-g84x-mcqj-x9qq
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-770: Allocation of Resources Without Limits or Throttling
Affected Product Aiohttp
Package Ecosystem PyPI
Published Date
Last Updated

How to Fix CVE-2025-69229

To remediate this vulnerability, upgrade all affected Aiohttp dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

aiohttp fixed: 3.13.3 
pip install aiohttp>=3.13.3
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show aiohttp

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2025-69229, inspect your installed packages using pip:

pip show aiohttp

Analyze the terminal output to locate any version of Aiohttp in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.13.3), your application is affected.

Note: The pip show aiohttp command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-770: Allocation of Resources Without Limits or Throttling, where the product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated. In Aiohttp, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Summary Handling of chunked messages can result in excessive blocking CPU usage when receiving a large number of chunks. ### Impact If an application makes use of the `request.read()` method in an endpoint, it may be possible for an attacker to cause the server to spend a moderate amount of blocking CPU time (e.g. 1 second) while processing the request. This could potentially lead to DoS as the server would be unable to handle other requests during that time. ----- Patch: https://github.com/aio-libs/aiohttp/commit/dc3170b56904bdf814228fae70a5501a42a6c712 Patch: https://github.com/aio-libs/aiohttp/commit/4ed97a4e46eaf61bd0f05063245f613469700229

CVE-2025-69229 Affected Aiohttp Versions

1 component(s)
Fixed Versions:
3.13.3
Product / Package Ecosystem Affected Versions Fixed Version
aiohttp
pypi/aiohttp
PyPI
< 3.13.3
3.13.3

References

GitHub Advisory / Wiki ADVISORY
https://github.com/aio-libs/aiohttp/security/advisories/GHSA-g84x-mcqj-x9qq
NVD — CVE-2025-69229 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-69229
Security Fix Commit FIX COMMIT
https://github.com/aio-libs/aiohttp/commit/4ed97a4e46eaf61bd0f05063245f613469700229
Security Fix Commit FIX COMMIT
https://github.com/aio-libs/aiohttp/commit/dc3170b56904bdf814228fae70a5501a42a6c712
Aiohttp Source Repository REPOSITORY
https://github.com/aio-libs/aiohttp

Frequently Asked Questions

What is CVE-2025-69229?
CVE-2025-69229 is a security vulnerability in Aiohttp involving AIOHTTP vulnerable to DoS through chunked messages under CWE-770: Allocation of Resources Without Limits or Throttling.
Which Aiohttp versions are affected?
Affected versions include releases prior to 3.13.3 across affected packages: aiohttp.
What version fixes CVE-2025-69229?
Upgrading to 3.13.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is aiohttp affected?
Yes, aiohttp is affected in releases prior to 3.13.3. Upgrade your dependency to 3.13.3 or later.
What CWE is associated with CVE-2025-69229?
CVE-2025-69229 is classified under CWE-770: Allocation of Resources Without Limits or Throttling (The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.).
How can I check PyPI dependencies for CVE-2025-69229?
Run the dependency tree command: 'pip show aiohttp'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-g84x-mcqj-x9qq",
  "modified" : "2026-01-06T16:06:58Z",
  "published" : "2026-01-05T23:13:29Z",
  "aliases" : [ "CVE-2025-69229" ],
  "summary" : "AIOHTTP vulnerable to DoS through chunked messages",
  "details" : "### Summary\n\nHandling of chunked messages can result in excessive blocking CPU usage when receiving a large number of chunks.\n\n### Impact\n\nIf an application makes use of the `request.read()` method in an endpoint, it may be possible for an attacker to cause the server to spend a moderate amount of blocking CPU time (e.g. 1 second) while processing the request. This could potentially lead to DoS as the server would be unable to handle other requests during that time.\n\n-----\n\nPatch: https://github.com/aio-libs/aiohttp/commit/dc3170b56904bdf814228fae70a5501a42a6c712\nPatch: https://github.com/aio-libs/aiohttp/commit/4ed97a4e46eaf61bd0f05063245f613469700229",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "aiohttp"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.13.3"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 3.13.2"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/aio-libs/aiohttp/security/advisories/GHSA-g84x-mcqj-x9qq"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-69229"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/aio-libs/aiohttp/commit/4ed97a4e46eaf61bd0f05063245f613469700229"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/aio-libs/aiohttp/commit/dc3170b56904bdf814228fae70a5501a42a6c712"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/aio-libs/aiohttp"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-770" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-01-05T23:13:29Z",
    "nvd_published_at" : "2026-01-06T00:15:48Z"
  }
}